TEST BANK FOR Mechanics of Aircraft Structures 2\\\'nd edition By C T sun Converted

The beam of a rectangular thin-walled section (i.e., t is very small) is designed to carry both bending moment M and torque T. If the total wall contour length (see Fig. 1.16) is fixed, find the optimum b/a ratio to achieve the most efficient section if L = 2(a + b) M = T and allowable allowable σ = 2τ . Note that for closed thin-walled sections such as the one in Fig.1.16, the shear stress due to torsion is abt T 2 τ = Figure 1.16 Closed thin-walled section Solution: (1) The ben...